Is there a role for inhaled corticosteroids and macrolide therapy in bronchiectasis?

Abstract

Bronchiectasis is characterised by permanent dilatation of the bronchi that arises from chronic inflammation predominantly caused by bacterial infection. This condition remains a major cause of excess respiratory morbidity and treatment is generally only partly successful. There is an urgent need for improved anti-inflammatory medication to treat bronchiectasis. Two potentially useful therapies are inhaled corticosteroids (ICS) and macrolides. The clinical trials that have been performed in bronchiectasis with these two medications can be considered to be preliminary data. This article reviews the anti-inflammatory properties, clinical efficacy and adverse effects of ICS and macrolides.ICS have a large number of potent anti-inflammatory properties. ICS remain the first-line treatment in asthma, reduce exacerbations in chronic obstructive pulmonary disease, and may improve lung function and symptoms in cystic fibrosis (CF). Four small clinical trials have assessed the effect of high-dose ICS on bronchiectasis. The main reported effect of these trials was a reduction in sputum volume and this may be a marker of decreased airway inflammation. Other possible benefits included decreased cough and sputum inflammatory cells/biomarkers. ICS have a relatively high prevalence of local adverse effects, and may be associated with ocular complications and osteoporosis. These adverse effects can be minimised by prescribing low doses of the medication. Macrolides have both antibacterial and immunomodulatory properties. Macrolides have less marked immunosuppressive properties than corticosteroids, and effects include decreasing mucous production, inhibiting virulence factors and biofilm formation of Pseudomonas aeruginosa, decreasing leukocyte numbers and altering inflammatory mediator release. Macrolides have been shown to be extremely effective in the treatment of diffuse panbronchiolitis, improve lung function and symptoms in asthma and CF, and reduce nasal polyps and secretions in sinusitis. Five small clinical trials have assessed the effect of macrolides on bronchiectasis. Reported benefits include reduced sputum volume, improved lung function and better symptom control. Macrolides are generally well tolerated, although they do have a number of drug interactions. There are concerns about the development of resistance, especially to non-tuberculous mycobacteria, with prolonged macrolide use. The evidence available suggests that both medications have a role in the management of bronchiectasis. More definitive trials of ICS and macrolides in bronchiectasis will clarify the likely benefit of these therapies.